Rumors are that the Kindle, Amazon's leaked E Ink e-reader, may be heavily subsidized to push the online retailer's e-book sales.

I would worry about the Kindle supporting non-proprietary formats then.

If Amazon prices the Kindle with the idea that they will "make up for their loss" with eBooks sales, then they will have to do something to force (or at least make it preferable) people to buy eBooks from Amazon.

Support for non-proprietary formats would make Amazon lose money on the Kindle. Of course, support for only DRM-emcumbered eBooks will also make it lose money.